C. Distillation          3. Common salt
    D. Polymerisation        4. Nylon
         A          B        C          D
    (a)  1          3        2          4
    (b)  2          1        3          4
    (c)  2          4        1          3
    (d)  3          2        1          4
Ans: (a)
60. The fresh urine has no smell while after some time it develops a strong odour because: [IAS 2003]
    (a) the urea of the fresh urine Is converted into uric acid
    (b) the uric acid of the fresh urine is converted into urea
    (c) conversion of urea to ammonia by bacteria
    (d) conversion of uric acid to creatinine by bacteria
Ans: (c)
61. Match the following:
    A. Exclusion principle                                         1. Balmer
    B. Uncertainty principle                                       2. Heisenberg
    C. Atomic spectrum of hydrogen atom in visible region          3. Schrodinger
    D. Wave mechanics                                              4. Pauli
         A          B        C          D
    (a)  1          4        2          3
    (b)  2          4        3          1
    (c)  4          1        2          3
    (d)  4          2        1          3
Ans: (d)
62. Match the following:
    Substances               Use
    A. Zeolite               1. Purgative
    B. Sodium thiosulphate 2. Safety matches
    C. Magnesium sulphate 3. Dry cell
    D. Graphite              4. Purification of water
                             5. Photography
         A          B        C          D
    (a) 3           5        2          4
    (b) 4           1        2          3
    (c) 3           2        1          5
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